Good adherence to therapy with statins reduces the risk of adverse clinical outcomes even among very elderly. Evidence from an Italian real-life investigation

BACKGROUND. Statins, are to date the most effective drugs for the treatment of hypercholesterolemia, and their important protective role in the prevention of cardiovascular (CV) morbidity and mortality is well-established [1]. Since people aged between 60 and 79 years were well represented in many trials, this applies also to elderly patients [2]. However, it does not apply to patients aged 80 years or older, because (i) none or few octogenarians have been included in outcome-based trials and (ii) evidence on the protective effects of statins among them is limited to only few observational studies with inconsistent results [3,4]. This represents an important limitation because the increasing life expectancy makes octogenarians the fastest growing subgroup of the population and, furthermore, this highly advanced aged subgroup accounts for a considerable portion of the overall CV events, hospitalizations and deaths [5]. AIM. To assess whether in individuals aged 80 years or older adherence to statins is accompanied by a reduced risk of all-cause mortality and major cardiovascular events. METHODS. A nested case–control study was carried out including a cohort of patients aged 80 years or older, who were under treatment with statins between 2008 and 2009, using the administrative databases of Lombardy region (Italy). Cases were the cohort members who experienced death or hospitalization for stroke, myocardial infarction or heart failure from the initial prescription until 2012. Up to five controls were randomly selected for each case. Logistic regression was fitted to estimate the odds ratio (OR), and its 95% confidence interval (CI), for the considered outcomes in relation to the adherence to therapy with statins, measured by the proportion of days covered (PDC). Four categories of adherence were employed (i.e., =75%), using the lowest one (